that's true, but some exercises are FAR BETTER than others
generally, the harder the exercise the better the exercise
In case you define 'harder' as more intense, I agree with you, but any exercise can be intense, it's just a matter of weight & focus.
There are differences between exercises when it comes to fiber recruitment, but that won't make one exercise 'far better' than another one.
IMO, compound exercises are overrated in effectiveness. They are good, but so are single joint movements, like curls, raises & extensions.